The invention relates to a blasting device comprising a flow passage for a carrier gas, the flow passage forming a blasting nozzle at its downstream end, and a supply line for liquid CO2, the supply line opening out into an expansion chamber that is formed coaxially in the flow passage.
EP 1 501 655 discloses a blasting device wherein the expansion chamber enters laterally into the flow passage. As an alternative, the possibility has been mentioned that the expansion chamber may be accommodated coaxially in the flow passage.
The expansion and evaporation of a part of the liquid CO2 in the expansion chamber produces evaporation chill, so that another part of the CO2 condenses to solid dry ice which then serves as a blasting medium that is carried along with the carrier gas and accelerated in the blasting nozzle. Such a device is suitable for efficiently and yet gently removing incrustations from surfaces. The cleaning effect depends critically on the number, size and velocity of the CO2 particles.